Railway signaling apparatus



Patented June 12, 1 928.

UNITED STATES PATENT OFFICE.

LESLIE HURST PETER AND COURTENAY HAROLD WISH EDMONDS, OF LONDON, ENG LAND, ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE UNION SWITGH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A. CORPORATION OF PENNSYLVANIA.

RAILWAY SIGNALING APPARATUS.

Application filed January 19, 1925, Serial No. 8,276, and in Great Britain February 14, 1924.

Our invention relates to electrically operated signaling apparatus for railways and the like, of the kind comprising light signals adapted to give two or more different signal indications according as one or other of a corresponding number of light signals is supplied with operating current, and has for its object to provide arrangements whereby a number of different signal indications may be given which is greater than the number of light signals employed.

According to our present invention the number of signal indications is increased by combining a multiple of the single signal indications or aspects hitherto given, so as to constitute one or more additional signal indications or aspects, this combination or combinations being preferably so arranged as to prevent a false indication from being given in the event of one or more of the component light signals failing from any cause.

Uur invention is illustrated by way of example in the accompanying drawings, of which Figs. 1, 2, 3, 4, 5 and 6 are diagrammatic views of various forms of the apparatus and .connections which may be employed in carrying our invention into practice.

Referring now first to the arrangement shown in Fig. 1, it will be seen that three signal lamps indicated at R, Y and G are provided, which when separately energized indicate st-op, caution and proceed respectively, in accordance with the usual convention. The apparatus also includes three relays indicated at A, A and A, adapted to be supplied with energizing current from any suitable point of control. The apparatus is also arranged to be connected to a suitable source of electric current through transmission conductors indicated at 1 and 4.

1 The operation of the apparatus is as t0lows':

When the relay A is de-energized a stop signal indication is given, a circuit being completed from the transmission conductor 1, through contact arm 2, of relay A, contact 3, signal lamp R to the other transmission conductor 4.

When the relay A is energized and the relays A and A are de-energized, a cantion signal indication is given, a circuit being completed from conductor 1, through contact arm 2, contact 5, contact arm 6 of relay A contact 7, and signal lamp Y to conductor 4-.

When the relays A, A and A are all onergized a proceed signal indication is given, a circuit being completed from the conductor 1, through contact arm 2, contact 5, contact arm 6, contact 8, contact arm 9, of relay A contact 10, conductor 11, signal lamp Gr, conductor 12, another contact arm 13 of relay A, contact 14:, to the other transmission conductor 4.

In addition to giving the usual three single signal indications as explained above the apparatus is also arranged to give a :lourth indication or aspect consisting of a combination of the signal lamps Y and G, this indication or aspect denoting a condition which is more restrictive than procoed and less restrictive than caution.

It will be evident that in the event of this additional signal indication or aspect being given by the supply of current to both the lamps Y and G simultaneously, the failure from any cause of the lamp Y would cause a false indication to be given, which would be less restrictive than the proper signal indication for the traffic conditions obtaining at the time. The apparatus shown in Fig. 1 is there!" ore so arranged that in the eventol' the lamp Y tailing when both the lamps Y and G are being snnultaneously supplied with operating current, the lamp G shall also be extinguished, thus ensuring the requisite safety in operation.

In order to give the additional signal indication or aspect constituted by the simultaneous energization of the lamps Y and G the relays A and A are energized the relay A being de-energized. A circuit is then completed from the conductor 1, through contact arm 2, contact 5, contact arm 6, contact 8, contact arm 9, contact 15 of relay A the primary winding 16 of a transformer T to the conductor 4. A circuit is also completed from one terminal of the secondary winding 17 of the transformer T, through conductor 18, a. second contact arm 19 of the relay A, contact 20, conductor 21. signal lamp G, conductor 1.2, contact arm 13, and contact 14; of relay A, conductor 22, signal lamp Y, and conductor 23 to the other terminal of the secondary winding 17. It will thus be seen that the signal lamps G and Y are supplied with operating current in series with one another, from the secondar winding 17 of the transformer T, the voltage at the terminals of the secondary winding 17 being arranged to be twice that for operating each of the signal lamps Y, G. Owing to the fact that these lamps areconnected in series with one another when both are illuminated simultaneously it will be understood that in the event of the lamp Y failing the lamp G will also be extinguished.

Referring now to the modified arrangement shown in Fig. 2 it will be seen that the stop signal lamp R is as in the arrangement previously described energized when the relay A is de-energized, a transformer T being however interposed between the lamp R and the conductors 1, 4. When the relay A is energized and the relays A and A are de-energized, a circuit is completed from the conductor 1 through contact arm 2 and contact 5 of relay A, contact arm 6 and contact 7 of relay A, the primary 24 of a transformer T, to conductor 4. A circuit is also completed from one terminal of the secondary 25, of transformer T through conductors 31 and 26, contact arm 13, and contact 27 of relay A", conductor 28, the caution signal lamp Y to the other terminal of secondary 25. The signal lamp Y is thus rendered operative to give a caution indication. When the relays A, A and A are all energized a circuit is completed from the conductor 1 through the contact arms 2, 6 and 9 of the relays, the primary winding 29 of a transformer T to the conductor 4, a circuit being also completed from one terminal of the secondary winding 30 of the transformer T through conductor 31, contact arm 19, contact 32, conductor 33, the proceed lamp G, to the other terminal of the secondary 30.

In the event of its being desired to give an intermediate signal indication by the illumination of the lamps Y and G simultaneously the relays A and A are energized and the relay A de-energized. A circuit is thus completed from the conductor 1, through contact arm 2, and contact 5 of the relay A, contact arm 6, and contact 8 of relay A, contact arm 9 and contact 34 of relay A conductor 35, one half of the secondary 24 of transformer T, to the other transmission conductor 4. The voltage of the transmission conductors 1 and 4 is thus impressed upon one half of the primary winding 24 of the transformer T with the result that the voltage across the secondary winding 25 of this transformer is that required for operating the lamps Y and G in series with one another. :Under these conditions a circuit is completed from one terminal of the secondary winding 25 of the transformer T through contact arm 19 and contact 36, of relay A, the signal lamp G, conductor 28 and signal lamp Y to the other terminal of the secondary 25. It will be seen that as in the arrangement of Fig. 1 in the event of the lamp Y failing from any cause the lamp G will also be extinguished.

Referring now to the arrangement shown in Fig. 3 the signal lamps G, Y and R are in this case arranged to be supplied with operating current through transformers T T and T respectively. T hese transformers are each provided with a secondary winding indicated at 37, 38, 39 and with primary windings indicated at 40, 41, 42 respectively. One terminal of each of the windings 40, 41, 42 .is connected to a common return conductor 43, the other terminals of the primary windings of the transformers being connected to control conductors 44, 45, 46 respectively. The magnetic circuits of the transformers T and T are also provided with a common \vindin 47, one terminal of which is connected to tie return conductor 43 and the other terminal to a control conductor 48.

In operation, when it is desired to energize the lamps G, Y-and R individually current is supplied to the corresponding control conductor 44, 45 or 46, this current traversing the primary winding of the corresponding transformer and the common return conductor 43. When, however, it is desired to energize the signal lamps G and Y simultaneously current is supplied through the control conductor 48 and the re-' turn conductor 43 to the winding 47 so that both the secondary windings 37 and 38 of the transformers T and T are energized, the signal lamps G, Y being consequently illuminated.

In the arran ement shown in Fig. 4 each of the lamps Y, R is provided with a separate control conductor 44, 45 and 46, and with a separate return conductor 43, 43 and 43', respectively. An inductive resistance or choke coil 49 is connected between the conductors 44 and 45, a similar inductive resistance or choke coil 50 being connected between the conductors 43 and 43 The control conductor 48 to which current is supplied when the signal lamps G and Y are energized simultaneously is connected to the middle point of the choke coil 49, the return conductor for this circuit being connected to the middle point of the choke coil 50 as indicated at 51. When it is desired to energize the signal lamps G, Y or R separately, current is supplied to the conductors 44, 43 or 45, 43 or 46, 43', whereas when a fourth signal indication is desired, in which both the signal lamps G and Y are illuminated simultaneously, current is supplied to the conductors 48 and 51. Under these latter conditions, the current traversing the lamps G and Y passes through the two halves of each of the choke coils- 49 and 50 in opposite directions, so that these choke coils ofi'er no appreciable impedance to the flow of current.

In the event, however, of the lamp Y failing, the circuit of the lamp G will include the lower half of each of the choke coils 49, 50 which is of sutiicient impedance to prevent the flow of the current necessary to illuminate the lamp G which in these circumstances remains unilluminated.

The arrangement shown in Fig. 5 is a modified form of the arrangement shown in Fig. 4, the choke coil 50 of this latter figure being omitted, and the three lamps G, Y and B being provided with a common return conductor 43, instead of a separate return conductor for each lamp circuit.

In the arrangement shown in Fig. 6, energizing current is supplied to the lamps R,

Y or, G individually, when the relay l is de-energized,' or when the relays A and A are energized and the relay A is de-ener gized, or when the relays A, A and A are all energized respectively, as will be readily apparent from the-figure.

'When it is desired to illuminate both the lamps Y and G simultaneously so as to give a corresponding fourth signal indication, the relay A is energized, the relays A and A being de-en'ergized. A circuit is then completed from the conductor 1, through contact arm 2, and contact 5 of the relay A, contact arm 6 and contact 7 of the relay A, contact 52, signal lamp Y, the energizing winding 53 of an additional relay B, conductor 54, to the other transmission conductor 4.

The relay B being thus energized a branch circuit is completed from the contact arm 19 of the relay A, contact 20, contact arm 55, of the relay B, contact 56, conductor 57, signal lamp G and conductor 58 to the transmission conductor 4. It will thus be seen that the supply of current to the signal lamp G is dependent upon the energization of the relay B, which in turn is dependent upon the circuit of the signal lamp Y being intact, so

that in the event of this signal lamp failing, the, circuit through the signallamp G will also be interrupted at the contact arm 55.

and contact 56.

The relays. A, A, A and B above referred to ma be of any suitabletype operated either e ectrically, electro-magnetically,

thermo-magnetically, electro-chemically or thermionically, as will be readily understood, and our invention is evidently not limited to the particular arrangements above described, which ma be varied in order to meet particular con in the scope of our invention.

ving now particularly describedand ascertained the'natur'e of our said invention and in what manner the same is to be performed, we declare that what we claim is 1. In a light signal, in combination, a plurality of signal lamps, means for lighting said lamps separately to give difierent signal indications, a transformer, means for at times supplying current to the primary winding of such transformer, and means effective when said primary winding is being supplied with current to supply current from the secondary winding of said transformer to two of said lamps simultaneously.

2. In a light signal, inicombination, a plurality of signal lamps, means for lighting said lamps separately to give different signal indications, a transformer, means for at times supplying current to the primary winding of such transformer, and means effective when said primary winding is being supplied with current to. connect two of said lamps in series with the secondary winding of said transformer;

3. In a light signal, in combination, a plutions, without exceednal lamps, means for at times rality of si lamps separately to give. difierlighting said ent signal cuit for the primary winding of said transformer arranged to be closed at times when said means are inefl'ective, and means for at times connectin two of said lamps in series with the secon ary winding of said transformer to give still another signal indication.

indications, a transformer, a cir- 4. In combination withthree relays and three signal lamps, means for lighting onelamp when oneof said relays is de-energized, means for lighting a second lamp when said one relay'is energized and a secondrelay is de-energized, means for energizing the third lamp when said three relays are all energized, and-means for simultaneously lighting said second and third lamps when said one relay and said second relay are both energized and said third relay is de-energized.

5. In combination with three relays and three signal lam 5, means for lighting one lamp when one 0 said relays is de-energized, means for lighting a second lam when said one relay is energized and a secon relay is deenergized, means for energizin the third lamp when said three relays are l energized, a transformer, means for energizing the primary winding of said transformer when said one relay nd said second relay are both energized an 1 and meansefl'ective when said second re ay is energized and said third relay is de-energized, forconnectin said second and third lamp in said third relay is de-ener 'zed,

series with t e secondary winding of said said lamps when one ofsaid re ays is de-en-.

ergized, a first transformer, means effective when said one relay 1s energized and a second relay is deenergized for energizing the primary winding of said first transformer means for connecting the secondary of sair transformer with a second signal lamp when said second relay is de-energized, a second transformer, means efi'ective when said three relays are all ener 'zed for energizing the primary winding 0 said second transformer, means-efl'ective when said third relay is en'- ergized for connecting the third signal lamp with the secondary winding of said second transformer, means effective when said one relay and said second relay are energized and said third relay is de-energized for energizing a part onl of the primary winding of said first trans ormer; and a circuit including said second lamp, said third lamp, the secondary of said first transformer and a contact closed de-energized.

7 In combination with two relays and two signal lamps, a transformer, means for energizing the entire primary winding of said transformer or a part only of such primary winding according as one or the other of said relays is de-energized, means for connectin one of said lamps with the seconda of sai transformer when said one relay is de-energized, and 'means effective when the remaining relay is de-energized for connecting both Sald lamps with the secondary winding.

In testimony whereof we aflix our signatures.

only when said third relay is LESLIE BURST PETER. COUR'I'ENAY HAROLD WISH EDHONDS. 

